Vibration translating device



H. C. HARRISON VIBRATION TRANSLATING DEVICE Jan. 7, 1936.

Filed Sept. I 29, 1934 FIG. 3

m M m6 N rR R NR 0 WA WWW W A Patented Jan. 7, 1936 PATENT OFFICEVIBRATION TRANSLATING DEVICE Henry 0. Harrison, Port Washington, N. Y.,assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y. acorporation of New York Application September 29, 1934, Serial No.746,674

7 Claims.

This invention relates to vibration translating devices such asrecorders and reproducers which have moving systems adapted to vibratein a plurality of modes.

The object of the invention is an e fiicient device of this type whichmay be readily used for reproducing (or recording) either hill and daleor lateral type records.

A recorder or reproducer according to the invention has a moving systemincluding a stylus which may vibrate either vertically or laterally torecord or reproduce either hill and dale or lateral cut records. Themagnetic circuit for supplying the necessary steady flux is of thedouble electromagnetic type and means are provided for reversing therelative direction of the flux at the sides of the vibratory element tomake the device responsive for either mode of vibration.

In the preferred structure a coil disposed above the stylus is supportedbetween main pole-pieces for both vertical and torsional vibrations andsur- I rounds a central pole magnetically connected to a common portionof the main pole-pieces. For lateral operation the central pole isneutral, but

for vertical operation, means is provided for reversing the current inone of the magnetizing .windings to make the main pole-pieces of thesame polarity in which case the return path for the combined flux fromthese pole-pieces is by way of the centralpole.

The device is well adapted for use as a reproducer for either lateral orhill and dale records without change in the operating position. Inchanging from one type of reproduction to the other it is necessarymerely to close the magnetizing switch in the proper position. If theoperator neglects to do this the device will be inoperative, but nodamage to either the reproducer or V the record will occur.

The invention will be more, clearly understood from the followingdetailed description andthe accompanying drawing in which:

Fig. 1 is a perspective view of an assembled translating deviceaccording to the invention;

Fig. 2 is a detailed View of the vibratory system; and

Fig. 3 is a diagram showing the magnetizing circuit for theelectromagnets.

Referring now to the drawing, the magnetizing windings l and H aredisposed on magnetic posed between the pole-pieces and extending into(Cl. I'm-100.41)

the coil I1 is a central pole-piece l8 magnetically connected to theyoke I4 by the bar Hi.

The vibratory system comprises the signal current coil I! wound on a cupmember 20 which is rigidly connected to a stylus 2l by a tubular piece22. This system is supported with the coil in the air-gap defined by thepole-pieces I5, l6

and I8 by parallel cantilever springs 23 and 24 secured to anon-magnetic supporting piece 25 and held in proper relative position bya screw 26 and a spacer 21. The spring assembly is in general similar tothat disclosed in my copending applications, Serial Nos. 742,761 and746,073, filed September 5, 1934 and September 29, 1934, respectively.The upper spring 23 is preferably V-shaped and made from thin sheetmaterial so that it is of low stiffness for vertical and torsionaldeflections but of relatively high stiffness for lateral deflections.The lower spring 24 should be free to deflect in all directions and isconveniently made from a single strand of fine wire.

The ends of the windings l0 and II are brought out to terminals 28-28and 29-29 respectively on the mounting frame 30 of the reproducer andfrom these terminals conductors extend within the reproducer supportingarm 3| to a current source as shown in Fig. 3. The magnetizing currentfor the windings may be obtained from a battery 32 or some other sourcesuch as a rectifier in the associated amplifying system. One of thewindings, In in this case, is directly connected to the current sourcebut the other winding is connected through a reversing switch 33 whichmay be conveniently located on the frame of the phonograph in which thereproducer is used, or if preferred it may be placed on the reproduceror the reproducer supporting arm.

When the translating device described above is to be used as areproducer on hill and dale or vertica cut records the switch 33 isclosed to the right and the currents through the windings l0 and II arein opposite directions so that the flux due to both windings flows fromone lateral pole-piece, 15 for instance, across the coil l1 and thecentral pole-piece l8 to the other lateral polepiece l6. As the stylus2| is vibrated vertically by the record. grooves the springs 23 and 24will both deflect vertically and the coil will be vibrated vertically inthe magnetic field to generate currents corresponding to the soundsrecorded on the record.

If a lateral cut record is to be reproduced the switch 33 is closed tothe left and the flux in the cores I2 and [3 then flows in the samedirection, that is, toward the pole-pieces l5 and I6 across the air-gapsand back to the yoke I4 through the pole-piece I8 and. the bar 59. Inthis case the stylus 2| will be vibrated laterally and the lower spring26 will deflect laterally but the upper spring 23 due to its highlateral and low torsional stifiness, will act as a fulcrum and the coilI! will oscillate, both sides of the coil adjacent the pole-pieces l5and I6 moving vertically but in opposite directions. But since the iiuxis now flowing toward the pole-piece 18 from both pole-pieces l5 and 16the electromotive forces generated in the opposite sides of each turn ofthe coil ll will again be additive and the currents in the coil willcorrespond to the sounds recorded on the lateral record.

While the invention has been described for purposes of illustration as auniversal phonograph reproducer, it will be apparent that a device ofthe general type shown is equally capable of being used as a recorderfor making either lateral or hill and dale records. Variousmodifications in the design will occur to those skilled in the art butthe invention is intended to be limited only by the scope of thefollowing claims.

What is claimed is:

1. In a vibration translating device, a generating element, a stylusconnected thereto, means for supporting the element for vibration indifierent modes corresponding to different modes of vibration of thestylus, means for producing flux transversely of the element, and meansfor reversing the direction of the flux at oneside of the element.

2. In a vibration translating device, the combination with a coil, astylus attached thereto, and means for supporting the coil for verticaland lateral vibrations of the stylus, of means for producing a magneticflux transversely of the coil, and means for reversing the direction oftheflux at one side of the coil.

3. In a vibration translating device the combination with a coil, astylus attached thereto, a magnetic core for the coil, and means forsupporting the coil for vertical and lateral vibrations of the stylus,of a pair of lateral pole-pieces for producing flux transversely of thecoil, and means for reversing the polarity of one of the polepieces.

4. The combination with a pair of lateral polepieces defining anair-gap, a coil, a stylusv attached thereto and means for supporting thecoil for vibration in difierent modes within the gap, of a centralpole-piece within the coil, means for producing fiux in the air-gap, andmeans for reversing the polarity of one of the lateral polepieces.

5. The combination with a pair of magnetizing coils, magnetic cores forthe coils having a common portion at one end and defining an air-gap atthe other end, a signal coil, a stylus attached thereto, and means forsupporting the coil for vertical and torsional vibrations in the gap, ofa magnetic member within the coil connected to the common portion of thecores, means for conmeeting the magnetizing coils to a source ofcurrent, and means for reversing the polarity of one of said coils.

6. In a universal phonograph reproducer, the

combination with a plurality of pole-pieces, a

generating element in operative relation to the pole-pieces, a stylussecured thereto and means for mounting the element to respond to bothvertical and lateral vibrations of the stylus, of means for producingflux in the pole-pieces and means for reversing the direction of theflux in one of the pole-pieces.

7. In a universal reproducer, the combination with a magnet systemcomprising a central polepiece, a pair of lateral pole-pieces definingtwo air-gaps on opposite sides of the central pole-,

piece, a yoke portion common to all the polepieces and a plurality ofwindings for producing flux in the pole-pieces, and a moving systemcomprising a coil surrounding the central pole-piece,- a stylus attachedto the coil and a plurality of

